I've checked my crash-reports folder and there's nothing there. Leading up to the error, I had just finished re-doing my Pneumaticraft system. I wired my kinetic compressor to turn off upon receiving a redstone signal, and shortly after, the problem arose after I checked my redstone energy cell's power level.
I've managed to recreate the situation in singleplayer and have tracked it down to an issue regarding the input Assembly IO unit picking up a non-standard item from the output's chest. In further detail, I had dismantled my Pneumaticraft system to move it somewhere else. I had placed everything inside of a chest. After I finished moving the system, I assumed that the output chest of the assembly machine was okay to hold Pneumaticraft items since nothing could come out of that chest. It turns out I was wrong. The input Assembly IO unit somehow decided to pull some item from that chest and tried to place it on the Assembly Platform. At this point, the server crashed and now I cannot get back on. Here is what the singleplayer crash-report shows in the recreated situation:
